A model railroad layout is currently on display at the Columbia Historic Preservation Society, 19-21 Second Street. The model buildings depicting Columbia circa 1920 - 1950 were constructed by Columbia artist Tony Segro, as was the re-creation of the Columbia Opera House (shown on this post).
Information from the display . . .
The former roundhouse, which sat just below the current Bootleg Antiques building (depicted top left).
A short video clip of the same.
A panoramic view. The roundhouse can be seen on the left.
Looking up Walnut Street (background), as it appeared in former days.